Visual Tamper-Evident Conical Screw Cap and Neck Finish

ABSTRACT

A tamper-evident cap is disclosed including a closure member and an annular wall depending outward therefrom to a bottom rim. Annular wall has a flange or sealing member extending inwardly adjacent to the closure member and a plurality of threads spaced apart and helically positioned to cooperate with respective threads of a container neck finish having substantially the same outward shape. A band is circumferentially positioned around the bottom rim including a pull tab and teeth. The pull tab extends from a part of the band and is preferably positioned within the circumference of the band. The teeth are mounted on a boss each tooth having an inner face angled acutely relative to the rim and being designed fit with the neck finish. A cap in combination with a neck finish having a vertical wall for sealing engagement with the cap annular flange is also disclosed.

TECHNICAL FIELD

The present invention relates to container caps and, more particularly,to tamper-evident caps for containers.

BACKGROUND

Various types of caps exist for removably sealing containers, such asblow-molded or injection molded containers. One such cap has spiralthreads extending along an interior surface which match spiral threadson the exterior of a compatible container neck. The threads enable a“screw-on” placement.

Caps may further provide a tamper-evident means, such as a tear band,that is intended to show evidence if the cap has been tampered with orpreviously removed. Many tear bands fit about the cap diameter andcooperate with ratchet teeth on the corresponding container neck finish.Typically, the tear band has a pull tab that must first be torn and thenremoved to permit the end user to twist the cap off from the neck.However, current cap threads and neck finish engagements are not alwayseffective to prevent the removal of the cap without first tearing thetear band. In such case, a so called tamper-evident cap can be removedfrom and reapplied to a container without leaving any visual evidencethat it has been tampered with.

Other tamper-evident bands, such as “drop bands,” are designed to remainon the container. When the cap is twisted the drop band drops down onthe neck revealing that it has been separated from the cap. However, theband does not always drop down as it should and instead may falselyappear to be connected with the bottom of the cap when it is not.

In addition to failing to provide visual evidence of a tampering, suchconfigurations are not always effective for self-centering the cap onthe container thereby resulting in a potential to cross thread duringthe capping operations. Thus there is a need to provide a tamper evidentcap for containers that attaches and releases with relative ease whilepreventing the cap to be removed without also tearing the tear band andstill providing visual evidence of tearing at point of purchase.

SUMMARY OF INVENTION

In general, one aspect of the present invention is directed to acontainer cap including a closure member having an annular wall taperedor conically depending from the periphery of the closure member. At theother end of the depending annular wall is positioned a tamper-evidenttear-off band. This band is secured to the annular wall by means of araised boss at the bottom of the annular wall. The band includes a pulltab and ratchet teeth adapted to cooperatively engage teeth on the neckfinish of the container to which it is fit to prevent removal of the capwithout first removing the band. According to aspects, the pull tab ispositioned within the circumference of the band, and, optionally, has abreak-tie securing it to a part of the band. At least one of the teethhas an inner face at an acute angle relative to the bottom rim.

Another aspect of the invention is directed to a neck finish formedhaving a conical wall that defines an opening therethrough. The wallincludes a first end that is typically open to the outside and adaptedto receive a cap, and a second end that terminates at the containerbody. At the first end there is a vertical wall with a lip extendinginwardly of the wall and preferably outwardly of the plane of theopening to provide a secondary seal when cooperating with a cap of thepresent invention.

In another aspect, embodiments of the invention include a bottle capadapted to cooperatively engage the neck finish. In another aspect, theinvention provides a tamper-evident cap having an outwardly conicalannular wall in combination with a neck finish having substantially thesame angular taper.

Other objects, features, aspects and advantages of the present inventionwill become better understood or apparent from the following detaileddescription, drawings, and appended claims of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a top perspective view of a cap according to embodiments ofthe present invention.

FIG. 2 shows an elevation of a cap and a bottle neck finish according toembodiments of the present invention.

FIG. 3 shows a partial sectional view of the cap and neck finish andshown in FIG. 1 taken substantially along line A-A of FIG. 1 accordingto embodiments of the present invention.

FIG. 4 shows a bottom plan view of a cap according to embodiments of thepresent invention.

FIG. 5 shows a top plan view of a cap according to embodiments of thepresent invention.

FIG. 6 shows a enlarged detailed view of an interior portion of the capaccording to embodiments of the present invention.

FIG. 7 shows a bottom plan view of a neck finish according toembodiments of the present invention.

FIG. 8 shows a top plan view of a neck finish according to embodimentsof the present invention.

EXAMPLES OF THE PRESENT INVENTION

As shown in FIG. 1, an embodiment of the present invention includes abottle cap 30 that can be used for sealing a container (not shown). Cap30 has a closure member 31 at one end and an annular wall 32 dependingfrom the perimeter thereof and terminating with a bottom rim 35 at itsother end. Closure member 31 is substantially circular and is designedto cover the mouth or opening in a neck finish 50 of a container 10, asshown for example in FIGS. 2 and 3, and includes depending valve 48. Anannular flange 41 extends circumferentially from the closure member 31along wall 32 at an acute angle relative to the plane of member 31.

A visual tamper-evident band 34 extends around the bottom rim 35 ofannular depending wall 32. In an embodiment, annular wall 32 tapersoutwardly from closure member 31 to band 34 and/or has a generallyconical shape. The degree of tapering or conical structure depends, inpart, on the dimensions of the container, particularly the neck finish,with which the cap 30 is used. In an example, annular wall 32 tapers atan angle of about 5° to about 20°; and, in specific example, annularwall 32 tapers outwardly to rim 35 at about 8°. In tests involving anapproximately 38 millimeter cap, annular walls having an angle greaterthan above 11° were less effective in providing the advantages of thisinvention. The angle can be further adjusted for a 28 or 48 millimetercap, or other sized cap, as such size is commonly referred to in theindustry. The taper or conical structure of the cap and neck finishpermits the cap to self-center on the neck during the capping process.The cap can be made from plastic such as high or low densitypolyethylene or any other resilient material that is suitable forsecuring a cap to a container.

The visual tamper-evident band 34 includes a pull tab 36, extending froma part of the band 34, and ratchet teeth 39 aligned along an interiorsurface thereof. The band 34 attaches to the bottom rim 35 of theannular wall 32 with at least one boss 37 with a connection sufficientto affix the band thereto while also permitting the band to be torn fromthe wall to allow removal of the cap from the neck finish. In anexample, multiple raised bosses 37 run horizontally radially across thebottom rim 35 of cap 30 and affix to the corresponding ratchet teeth 39.As shown for example in FIG. 4, the tips or corners of ratchet teeth 39connect to an outward end of bosses 37. In an embodiment, attachment ofthe ratchet teeth to the bosses 37 cooperates in preventing the cap frombeing removed from the container 10 without first removing the tear band34.

Pull tab 36 is positioned within the circumference of the band 34 andattached continuous therewith at break-tie 38. Optionally, in anexample, a second break-tie joins a top portion of band 34 to the bottomrim 35 of the cap opposite break-tie 38. In an example, the pull tab 36is upwardly or downwardly extending. The extension of pull tab 36 incombination with the tapering or conical structure of annular wall 32enables tab 36 to remain generally within the same circumference of theband 34 as shown, for example, in FIGS. 4 and 5. This placement on band34 leaves an open space between the wall 32 and the tab 36 in which theuser can grab hold of the extending portion of the tab 36 and pull thetab 36 disengaging the break-tie 38 from the band 34. The conical shapeallows the tab 36 of band 34 to be tucked inward toward annular wall 32.Additionally, unlike many prior tamper-evident caps which have pull tabsthat protrude beyond the band's outer circumference, the present cap isnot hindered by such protrusion enabling it to move freely in anorientation roll sorter for positioning and appropriately orienting themfor application to a container. Further, such circumferentialpositioning prevents the cap tabs from interlocking or entangling withtabs of other caps in the chute or sorter. Working in the 360 degreeband circumference gives the cap an opportunity to roll withoutinterference between the cap and orientation process.

In an example, a user removes cap 30 by sliding a finger down alongannular wall 32 pushing tab 36 outward, and pulling tab 36 away fromwall 32 and severing break-tie 38 from a portion of band 34. Absence ofbreak-tie 38 provides the user with visual evidence that the cap hasbeen tampered with or removed.

Ratchet teeth 39 are adapted to engage teeth 58 on the neck finish 50 ofa container 10, as shown, for example, in FIG. 2. The ratchet teeth 39are attached to the bottom of the cap body at raised bosses 37 whichsecure band 34 to the cap. Each ratchet tooth 39 has an inner face 40.Inner face 40 is positioned at an acute angle α from the plane of cap10. In an example, angle α is about 10° to about 20°, and, in anotherexample, angle α is more preferably about 15° from the plane of the capgoing inwardly. However, angle α could vary beyond these ranges if a caphaving a longer profile is needed, for example, if a longer annular wallis used. That angle determination can be made within the scope of thisinvention by persons of ordinary skill in the art without undueexperimentation. Angle α is important in the self-centering of the capon the neck finish. The inner face 40 is designed, in part, to permitcap 30 to expand over an outer edge of the neck finish when beingapplied to container 10. This helps to self center the cap on thecontainer from a slight angle inputted by a capping machine to thusprovide proper thread engagement.

Cap 30 includes an annular flange 41 positioned on the annular wall 32proximate to closure member 31. Annular flange 41 extends at an angle βrelative to the closure member 31. In an example angle β is in the rangeof about 30° to about 60°. In another example, angle β is about 45°.According to aspects of the invention, inner face 40 and annular ringflange 41 are located and dimensioned to engage and cooperatively securecap 30 onto the neck finish of a container. For example as illustratedin FIG. 3, cap inner face 40 and flange 41 cooperate with an annularflange 59 and an annular lip 57 of the neck finish 50 of a container 10,respectively, when the cap is screwed onto the neck finish. In anexample, the inner face 40 sits between the bottom end of the neckfinish 56 and a protective rim 70 on the container 10.

Several sets of helically spaced threads 43 are positioned on the innersurface of annular wall 32 generally extending from the closure member31 proximate to the annular flange 41 to the bottom rim 35. Each thread43 has a respective lead opening 44 and tail 45. The threads 43 aretapered toward lead openings 44 and tails 45. The conical or taperdesign of annular wall 32 and threads 43 helps allow the cap 30 to selfcenter on the neck of a container. Further, the tapered or conicaldesign minimizes the chance that threads would over strip or crossthread. In an example, there are at least five thread leads 44 each onebeginning at about 72 degrees around the inner surface of annular wall32. Preferably, threads 43 extend more than 90 degrees and less than 360degrees around the inner surface of annular depending wall 32. In anexample, threads 43 extend around the inner surface about 180 degrees.According to an aspect of the invention, threads 43 project inwardlyfrom annular wall 32 at an angle γ. Angle γ is in the range of about 30degrees to about 90 degrees, and, preferably, angle γ is about 60degrees, plus or minus five degrees.

Depending from closure member 31, is annular valve 48. Annular valve 48is positioned at a distance from annular wall 32 that will permitinsertion of the top portion of a container neck finish to fittherebetween. In an example, the valve 48 is spaced from an internalsurface of the annular depending wall at a distance that is sufficientto engage an annular lip on the neck finish. In an example, this joindercreates a corner area 47 for accepting the “updraft” from the top rim ofthe neck of a container. Typically, the corner area 47 provides a rightangle into which the top rim fits sufficiently to create a sealingengagement. In an example, this rim and the top portion of the containerneck fit comfortably between the annular flange 41 and annular valve 48.The valve 48 extends to a point near to the start of threads 43. In anexample, valve 48 includes a taper 49 which facilitates initialengagement of the valve to the inner periphery of the neck finish of acontainer opening.

In another example of cap 30, annular valve 48 may be eliminated. Inthis example it will be preferable to also eliminate annular ring valve41. With removal of annular valve 48, and preferably ring flange 41, acircular sealing member, not shown, would be positioned substantiallywith closure member 31 to provide a seal between said closure member andopening 53. The sealing member is preferably a disk made of foils, foam,paper or the like. This example entails an additional step of thesealing member placement prior to the bottle capping operation.

In an example, cap 30 has outer ribs or serrations 46 extending alongthe exterior of annular wall 32. Generally serrations 46 extend from theperimeter of closure member 31 to the bottom rim 35. According toembodiments, serrations 46 taper toward the bottom rim 35 and have anouter spine that is substantially perpendicular to the plane of theclosure member 31. In an example, sets of serrations 46 are positionedequidistant about the circumference of annular wall 32. In an example,each set contains two to four serrations. In an example there are eightsets of serrations, the majority of which sets contain about two, andpreferably three, serrations 46. Serrations 46 in combination withthreads 43 prevent the cap from nesting when stacked with other caps.

According to aspects of an embodiment, the present invention includes aconical neck finish 50 of a container 10, as illustrated for example inFIG. 2. Neck finish 50 preferably has substantially the same tapered orconical angle of revolution as cap 30. Neck finish 50 includes anannular wall 52 defining therethrough a cylindrical opening 53 having afirst end 54 and a second end 56. First end 54 provides access toopening 53. Near opening 53, a vertical wall 55 and an annular lip 57are provided at the first end of the annular wall 52. Vertical wall 55is positioned substantially perpendicular to the plane of a fittingclosure member 31. Slight variance in the perpendicular is acceptable;however, a significant divergence may prohibit engagement of the cap tothe neck finish. In an example, the vertical wall varies at less thanabout an 8 or 10 degree angle, and, preferably it is perpendicular.Annular lip 57 extends inward from the vertical wall 55 and terminatesat the inner diameter 51 of the container. The inner diameter 51 is alsosituated at the end of the updraft. Preferably the annular lip 57extends inwardly at a slight outward angle from the plane of the firstend as shown in FIGS. 2 and 3.

In an example, when cap 30 is applied to the neck finish 50, annularvalve 48 is spaced apart from annular wall 32 a distance which isrepresented by the difference in the radial distance from the outer edgeof annular wall 32 at its closure end and the center of a container neckopening and the inner edge of the lip 57. The outer diameter of valve 48together with annular flange 41 on the cap enhance sealability of capclosure member 31 by creating pressure on the container neck. In anembodiment, as the valve 48 penetrates the inner diameter 51 pushesinward to opening 53, updraft of 57 deflects inward and vertical wall 55is pushed outward on the neck. Annular flange 41 actuates on the topportion of vertical wall 55 pushing it back thereby creating a secondaryseal.

Positioned adjacent to the second end 56 is at least one set of annularratchet teeth 58 to provide a tamper evident grip for the cap. Ratchetteeth 58 may be positioned around the entire circumference of the secondend 56 of the neck or only a portion thereof. In an embodiment, thereare two sets of teeth 58 positioned about end 56 with a flat wall 69separating them at each end of both. Each set consists of eight totwelve teeth 58, although they need not have an equal number. In anexample, each set has ten teeth. In an embodiment, the teeth 58 of twodifferent sets of teeth 58 are positioned in opposing directions toprevent “backing off” the cap from the bottle neck. Ratchet teeth 58 areadapted to cooperatively engage corresponding teeth 39 on thetamper-evident band 34 positioned on the mating cap 30.

In an embodiment of the invention, an annular ring flange 59 ispositioned substantially adjacent to the plane in which the annularratchet teeth 58 are provided. This flange 59 in cooperation withannular lip 57 provides a means for securing the cap to the bottle. Inan example, the cap snaps over and locks onto the neck finish.

Helically extending between the annular lip 57 and the annular ringflange 59, are at least three threads 64 leading at points 66 andterminating at points 67, adjacent first end 54 and annular ring flange59, respectively. Threads 64 are helically spaced in contiguousrelationship as shown in FIG. 2. In an example, there are five threads64. In embodiments, each thread 64 extends around the circumference ofannular wall 52 at a degree corresponding to that of cap threads 43.

In an example, when cap 30 is applied to the neck finish 50 of acontainer, the threads of the cap contact the top of the threads of thecontainer neck finish before the valve 48 or flange 41 contact theinside dimension of the container. In an example, cap threads 43 engagethe bottle threads 64 before the ratchet teeth 58 engage. The capthreads engage with the rotating of the cap engaging the threads of neckfinish and engaging the cap 30. Valve 48 cooperates with flange 41 toseal contents when lip 57 pushes against the valve during engagement ofthe threads.

The protective rim 70 extends downwardly and outwardly from the ratchetteeth 58. The protective rim 70 protects the tamper-evident band 34 fromintrusion, for example, by an object that could be used to dislodge thetamper-evident band 34 without tearing it and enable the cap to releasefrom the container. The neck finish can be made of plastic such as highor low density polyethylene of any other material suitable for use withthe contents of the container. The material may be the same as that ofthe container.

Cap 30 when used in combination with neck finish 50 of the presentinvention provides a seal that is particularly well suited to standardbeverage containers, such as blow molded milk containers. When properlysealed, air will not penetrate through the container opening. Use of thetamper-evident band 34 with break tie 38 makes it extremely difficult,if not impossible, to tamper with the contents of the bottle withoutindicating evidence thereof on the cap. Use of optional second break-tieprovides a further security seal.

The embodiments of the invention shown and described in the abovefigures are exemplary of numerous embodiments that may be made withinthe scope of the invention. It is to be understood that the detailedembodiments, figures and examples are presented for elucidation and notlimitation. The invention may be otherwise varied, modified or embodiedwithin the scope of the invention as defined in the appended claims.

1. A tamper-evident cap comprising: a closure member and an annular walldepending from the closure member, said wall tapering outward to abottom rim to cooperate with a neck finish having substantially the sameangular taper; an annular flange positioned around an interior surfaceof the annular wall adjacent to the closure member; at least one bossproximate said bottom rim; a band circumferentially positioned aroundthe bottom rim including teeth diverted inwardly and at least one toothbeing mounted on said at least one boss, wherein the teeth are adaptedto engage cooperative teeth on a neck finish, each said tooth having aninner face, said inner face being positioned at an acute angle relativeto the bottom rim; and a plurality of threads spaced apart and helicallypositioned on an interior surface of the annular wall extending fromabout the annular flange to proximate said bottom rim.
 2. The cap as inclaim 1 further including a pull tab extending upwardly or downwardlyfrom a part of the band.
 3. The cap as in claim 2 wherein the pull tabis positioned within the circumference of the band.
 4. The cap as inclaim 2 wherein the pull tab is attached to the band with at least onebreak-tie.
 5. The cap as set forth in claim 1 wherein a sealing means ispositioned in juxtaposition with said closure member.
 6. The cap as inclaim 1 further including an annular valve depending from the closuremember and spaced apart from an interior surface of the annular wall. 7.The cap as in claim 1 further including serrations on an exteriorsurface of the annular wall.
 8. The cap as in claim 7 wherein theserrations taper toward the bottom rim and have an outer dimension thatis substantially perpendicular to the plane of the closure member. 9.The cap as in claim 1 wherein the flange extends relative to the closuremember at an angle of about 30 degrees to about 60 degrees.
 10. The capas in claim 1 wherein the threads project inwardly at an angle of about30 to 90 degrees.
 11. The cap as in claim 1 wherein the acute angle ofinner face is about 10 to about 20 degrees.
 12. The cap as in claim 1wherein the boss extends horizontally radially across the bottom rim.13. The cap as in claim 1 wherein said taper provides a conical shape.14. The cap as in claim 1 in combination with a neck finish for acontainer, wherein the neck finish comprises: an annular wall having afirst and second end, defining a cylindrical opening therethrough, andhaving an annular lip extending inwardly toward said opening from avertical wall at the first end thereof; at least one set of ratchetteeth positioned around a portion of an outer surface of the neckannular wall at the second end; and multiple threads angularlypositioned on an exterior surface of the neck annular wall between thefirst end and the ratchet teeth.
 15. The cap as in claim 14 wherein thevertical wall is adapted to associate or engage the annular flange onthe cap.
 16. The cap as in claim 14 wherein the lip terminates with aninner end adapted to contact a valve of the cap.
 17. The cap as in claim14 wherein the neck finish further includes an annular ring flangeextending substantially around the annular wall adjacent to the set ofratchet teeth.
 18. The cap as in claim 14 further including a protectiverim 70 extending around the exterior surface of the neck annular walland projecting outward from the set of ratchet teeth.
 19. The cap as inclaim 14 wherein the cap further includes a valve depending from theclosure member spaced apart from an internal surface of the annulardepending wall a distance sufficient to engage an annular lip of theneck finish.
 20. A tamper-evident cap comprising a closure member and anannular wall depending therefrom, said wall tapering outwardly to abottom rim to cooperate with a neck finish having substantially the sameangular taper; a sealing member juxtapositioned substantiallycoextensively with said closure member; at least one boss proximate saidbottom rim, a band circumferentially positioned mount said bottom rimhaving teeth directed inwardly and at least one tooth being mounted on aboss and adapted to engage teeth on a neck finish of a bottle, each ofsaid teeth having an inner face positioned at an acute angle relative tothe bottom rim, and a plurality of spaced apart threads helicallypositioned on the inner surface of the annular wall from a pointpositioned away from said sealing member to about said bottom rim. 21.The cap as set forth in claim 20 wherein said sealing member comprises adisk.